JPH10212552A - Member for steel making hot rolling equipment excellent in wear resistance and corrosion-resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for steel making hot rolling equipment excellent in wear resistance and corrosion-resistance and used for wrapper rolls, pinch rolls, mandrels, steel sheet carrying rollers or the like. SOLUTION: Molten metal 19 having components contg., by weight, 0.5 to 2.5% C, 0.3 to 3.0% Si, 0.3 to 3.0% Mn, 2.0 to 15.0% Cr, 2.0 to 15.0% Mo, 2.0 to 15.0% V, <=10.0% W, <=10.0% Co and one or >= two kinds selected from the groups of 0.5 to 5.0% Nb, 0.5 to 5.0% Ti and 0.5 to 5.0% Zr, and the balance substantial Fe with inevitable impurities and moreover satisfying -2<=C-(0.06 Cr+0.063Mo+0.033W+0.236V+0.129Nb+0.251Ti+0.132Zr)<=0 is solidified to the external surface of a base material 17 to form a build-up welding layer 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member for a hot rolling equipment for steel making which is excellent in wear resistance and corrosion resistance used for a wrapper roll, a pinch roll, a mandrel, a steel sheet conveying roller and the like for a hot rolling equipment for steel making. .

[0002]

2. Description of the Related Art A wrapper roll for a coiler, a pinch roll, a mandrel, and a steel sheet conveying roller in a hot rolling mill for steelmaking are subjected to the impact force of the front end of the steel sheet as the steel sheet is intermittently rolled. In general, the peripheral speed of these rolls has a speed difference from the steel plate in order to improve the winding shape of the steel plate, further prevent operation troubles such as miscoils, and improve the initial winding. As a result, slip occurs between the roll and the steel plate. In addition, the steel sheet transport rollers disposed before and after the rolling mill stand cause a severe slip between the steel sheet and the steel sheet when the steel sheet bites into the rolling mill or reverses. on the other hand,
It has a structure in which high-pressure water for removing scale generated on the surface of a high-temperature steel sheet before rolling and cooling water for cooling the steel sheet and the roll surface are applied to these roll surfaces. To improve the abrasion resistance and corrosion resistance of these roll surfaces, see “Recent Hot Strip Manufacturing Technology in Japan” (The Iron and Steel Institute of Japan, issued August 10, 1987), pages 295 and 296. [C
r] <13% by weight, mainly 3-7% by weight of Cr
r-based overlay materials have been employed. Specifically, on the surface of a roll base material made of structural steel, cast steel, etc., in addition to [Cr], a composition of [C] <0.4% by weight and [Mo, V] <10.0% by weight After the iron-based material is coated by the welding overlay method, the hardness is set to Hs> 70 by heat treatment, or
The hardened layer was covered by a method of casting an iron-based material having the same composition.

Japanese Patent Application Laid-Open No. 3-23810 proposed by the present applicant
No. 7, [C] 0.3 to 1.0% by weight, [S
i] 0.3 to 1.5% by weight, [Mn] 0.3 to 1.5% by weight, [Ni] 0.5 to 3.0% by weight, [Cr] 3.0
To 8.0% by weight, [Mo] 0.5 to 3.0% by weight, V,
Iron for coilers manufactured by a special casting method in which a molten metal containing 0.1 to 1.0% by weight of one or more of Nb and W is welded to the outer surface of a base material and solidified by cooling. The base roll material has a durability 2.5 times or more as compared with a conventional Cr-based weld overlay. Also,
In Japanese Patent Application No. 7-256836, [C] is 0.5 to 2.0% by weight and [Si] 0.1 to 1.
5% by weight, [Mn] 0.1 to 1.5% by weight, [Cr]
2.0-15.0% by weight, [Mo] 2.0-10.0% by weight, [V] 1.0-8.0% by weight, [W] 1.0-1.
An iron-based abrasion-resistant and corrosion-resistant roll material containing 0.0% by weight and [Co] of 1.0 to 15.0% by weight was proposed, and improvement in wear resistance and corrosion resistance was achieved.

[0004]

However, in recent years,
In the hot rolling line of steel, high pressure, high speed continuous rolling, increase of difficult-to-roll materials such as stainless steel and silicon steel, or thinning of products are progressing, and as a result, the use conditions of rolls are becoming severer. I am following. For example, a wrapper roll for a coiler, a pinch roll, a mandrel, and a steel sheet conveying roller are severely abraded and corroded, and there is an increasing need for improved abrasion resistance and corrosion resistance. Due to the increase in the wear and corrosion, the surface properties of the steel sheet product are deteriorated, and the frequency of replacing the rolls is increased, and the rolling efficiency is reduced. The Cr-based overlay material described in the above publication does not always satisfy the increasingly high required level of the hot rolling line.
It is necessary to further improve the durability of the roll material manufactured by the special casting method described in Japanese Patent Application No. 38107 and Japanese Patent Application No. 7-256836.

The present invention has been made in view of the above circumstances, and has improved wear resistance and corrosion resistance to a high level, and has excellent durability such as a wrapper roll for a coiler, a pinch roll, a mandrel, and a steel sheet conveying roller. Wear resistance,
An object of the present invention is to provide a member for hot rolling equipment for steel making which has excellent corrosion resistance.

[0006]

According to the present invention, there is provided a semiconductor device comprising:
The wear resistance of the described steel member for hot rolling equipment with excellent corrosion resistance uses a combination mold in which a cooling mold is integrally disposed below a refractory heating mold having an electromagnetic induction heating coil. A solid or hollow base metal made of steel is inserted concentrically and vertically into the interior of the combination mold, and a separately prepared molten metal is injected into an annular space around the base metal, so that the base material is intermittently inserted. While the molten metal is welded to the outer surface of the base material, and solidified by cooling to form a build-up layer on the outer periphery of the base material, and subjected to a predetermined heat treatment and machining to produce a heat resistant material. Abrasion, a member for hot rolling equipment with excellent corrosion resistance, wherein the component of the molten metal is [C] 0.5 to
2.5% by weight, [Si] 0.3 to 3.0% by weight, [M
n] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0
% By weight, [Mo] 2.0 to 15.0% by weight, [V] 2.
0 to 15.0% by weight, [W] 10.0% by weight or less, [C
o] 10.0% by weight or less, and [Nb] 0.5 to 5.0.
%, [Ti] 0.5 to 5.0% by weight, [Zr] 0.
One or more selected from the group consisting of 5 to 5.0% by weight, the balance substantially consisting of Fe and unavoidable impurity elements, and -2 ≦ C- (0.06Cr + 0.063M).
o + 0.033W + 0.236V + 0.129Nb +
0.251Ti + 0.132Zr) ≦ 0 is satisfied.

According to a second aspect of the present invention, there is provided a member for hot rolling equipment having excellent wear resistance and corrosion resistance, in which a cooling mold is integrally disposed below a refractory heating mold having an electromagnetic induction heating coil. Using a combination mold, a solid or hollow base material made of steel is inserted concentrically and vertically into the interior of the combination mold, and a separately prepared molten metal is injected into an annular space around the base material, The base material is intermittently lowered and solidified by cooling while welding the molten metal to the outer surface of the base material to form a build-up layer on the outer periphery of the base material, a predetermined heat treatment,
A member for an iron-making hot rolling facility having excellent wear resistance and corrosion resistance manufactured by machining, wherein the component of the molten metal is [C] 0.5 to 2.5% by weight, [Si] 0.3 ~
3.0% by weight, [Mn] 0.3 to 3.0% by weight, [C
r] 2.0-15.0% by weight, [Mo] 2.0-15.
0% by weight, [V] 2.0 to 15.0% by weight, [W] 1
0.0% by weight or less, [Co] 10.0% by weight or less, [N
i] 0.5 to 10.0% by weight, the balance being substantially composed of Fe and inevitable impurity elements, and -2 ≦ C- (0.
06Cr + 0.063Mo + 0.033W + 0.236
V) ≦ 0 is satisfied.

According to a third aspect of the present invention, there is provided a member for an iron making hot rolling facility having excellent wear resistance and corrosion resistance, wherein a cooling mold is integrally formed below a fire resistant heating mold provided with an electromagnetic induction heating coil. Using the placed combination mold, a solid or hollow base material made of steel is inserted concentrically and vertically into the inside of the combination mold, and a separately prepared molten metal is injected into an annular space around the base material. And lowering the base material intermittently,
While the molten metal is being welded to the outer surface of the base material, it is solidified by cooling to form a build-up layer on the outer periphery of the base material, and is subjected to predetermined heat treatment and machining to produce wear resistance and corrosion resistance. It is a member for an iron making hot rolling facility excellent in heat resistance, wherein the component of the molten metal is [C] 0.5 to 2.5% by weight, [Si]
0.3 to 3.0% by weight, [Mn] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0% by weight, [Mo] 2.0
-15.0% by weight, [V] 2.0-15.0% by weight,
[W] 10.0% by weight or less, [Co] 10.0% by weight or less, [Ni] 0.5 to 10.0% by weight, and [Nb]
One or more selected from the group consisting of 0.5 to 5.0% by weight, [Ti] 0.5 to 5.0% by weight, [Zr] 0.5 to 5.0% by weight, and the balance Consists essentially of Fe and unavoidable impurity elements, and -2 ≦ C- (0.06C
r + 0.063Mo + 0.033W + 0.236V +
0.129Nb + 0.251Ti + 0.132Zr) ≦
0 is satisfied.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is a schematic explanatory view of a combination mold that can be suitably used for manufacturing a member for a hot rolling equipment having excellent wear resistance and corrosion resistance according to an embodiment of the present invention, and FIG. FIG. 3 is a graph showing the weight loss per unit area of the roll using the comparative material, and FIG. 3 is a graph showing the corrosion loss per unit area of the roll using the inventive material and the comparative material. First, a combination mold 10 according to an embodiment of the present invention, which can be suitably used for manufacturing a member for a hot rolling equipment for steel making having excellent wear resistance and corrosion resistance, is shown in FIG.
As shown in the figure, a refractory heating mold 13 having a hollow annular refractory frame 12 in which an electromagnetic induction heating coil 11 is disposed.
And a cooling mold 14 disposed below the refractory heating mold 13 and having a coaxial inner hole. The cooling mold 14 has a lower part which is moved up and down by a lifting means such as a hydraulic cylinder (not shown) and mounted on the upper part. An elevating device 16 for gradually lowering the member 15 for hot rolling equipment made of rolls is provided.

Using this combination mold 10,
When manufacturing the member 15 for steelmaking hot rolling equipment, a solid or hollow base material 17 is provided at the center of the combination mold 10.
Insert Next, the molten metal 19 of the overlay material prepared as the outer layer separately prepared in the melting furnace 18 is injected into the annular gap 20 between the base material 17 and the combination mold 10 while applying a current to the electromagnetic induction heating coil 11, The base material 17 is lowered intermittently. As a result, the molten metal 19 is sequentially cooled and solidified by the cooling mold 14 while being welded to the surface of the base material 17, and the overlay 21 is formed by a special casting method. Thereafter, machining is performed to an outer diameter slightly larger than the product, and then heat treatment such as predetermined quenching and tempering is performed, and further machining is performed to the product dimensions, thereby producing a member 15 for steelmaking hot rolling equipment. You. In this case, a borosilicate glass film 22 is formed in advance on the outer periphery of the base material 17, and the base material 17 is preheated by the electromagnetic induction heating coil 23 for preheating arranged on the combination mold 10, and the borosilicate By melting and firing the glass coating 22, the build-up layer 21 can be formed while keeping the surface of the base material 17 clean. In addition, in FIG. 1, 24 is a centering device, 25 is a fusion part, and 26 is a fusion flux.

Here, the components of the build-up layer 21, that is, the components of the molten metal 19, are as in the first embodiment [C]
0.5 to 2.5% by weight, [Si] 0.3 to 3.0% by weight, [Mn] 0.3 to 3.0% by weight, [Cr] 2.0 to
15.0% by weight, [Mo] 2.0 to 15.0% by weight,
[V] 2.0-15.0% by weight, [W] 10.0% by weight
Hereinafter, [Co] 10.0% by weight or less, and [Nb] 0.
5 to 5.0% by weight, [Ti] 0.5 to 5.0% by weight,
[Zr] One or more selected from the group consisting of 0.5 to 5.0% by weight, the balance being substantially composed of Fe and unavoidable impurity elements, and -2 ≦ C− (0.06Cr +
0.063Mo + 0.033W + 0.236V + 0.1
29Nb + 0.251Ti + 0.132Zr) ≦ 0.

Further, as a second embodiment, the component of the build-up layer 21, that is, the component of the molten metal 19 is [C] 0.5 to 0.5.
2.5% by weight, [Si] 0.3 to 3.0% by weight, [M
n] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0
% By weight, [Mo] 2.0 to 15.0% by weight, [V] 2.
0 to 15.0% by weight, [W] 10.0% by weight or less, [C
o] 10.0% by weight or less, [Ni] 0.5 to 10.0% by weight, the balance being substantially composed of Fe and unavoidable impurity elements, and -2 ≦ C- (0.06Cr + 0.063M).
o + 0.033W + 0.236V) ≦ 0.

Further, as a third embodiment, the component of the build-up layer 21, that is, the component of the molten metal 19 is [C] 0.5
~ 2.5 wt%, [Si] 0.3-3.0 wt%, [M
n] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0
% By weight, [Mo] 2.0 to 15.0% by weight, [V] 2.
0 to 15.0% by weight, [W] 10.0% by weight or less, [C
o] 10.0% by weight or less, [Ni] 0.5 to 10.0% by weight, and [Nb] 0.5 to 5.0% by weight, [Ti]
0.5 to 5.0% by weight, [Zr] 0.5 to 5.0% by weight
One or more selected from the group consisting of: and the balance substantially consists of Fe and unavoidable impurity elements, and -2.
≤C- (0.06Cr + 0.063Mo + 0.033W
+ 0.236V + 0.129Nb + 0.251Ti +
0.132Zr) ≦ 0.

Next, the components of the build-up layer 21, that is, the melt 19
The reason why the component is limited as described above will be described. (1) C: 0.5~2.5 wt% C is Cr, Mo, W, V, Nb, Ti, Zr , etc. and M ₂₃
It forms extremely hard carbide of C ₆ , M ₂ C and MC type and improves wear resistance. In addition, it forms a solid solution in the matrix, improves the quenching properties, and improves the strength and hardness of the matrix.
If the amount is less than 0.5% by weight, the amount of carbides decreases and the wear resistance decreases. If the amount exceeds 2.5% by weight, the amount of net-like carbides increases, the toughness decreases, and the amount of Cr carbides increases. This is because the amount of dissolved Cr in the matrix decreases, and the corrosion resistance decreases. (2) Si: 0.3 to 3.0% by weight Si is required as a deoxidizing agent, but if it is less than 0.3% by weight, it has no effect, and if it exceeds 3.0% by weight, it has a deoxidizing effect. Because of saturation, the lower and upper limits are 0.3 and 3.0, respectively.
% By weight.

(3) Mn: 0.3 to 3.0% by weight Mn not only functions as a deoxidizing agent, but also fixes harmful S mixed as an impurity as MnS. When the content exceeds 3.0% by weight, no further effect is obtained. Therefore, the lower limit is 0.3% by weight and the upper limit is 3.0% by weight.
And (4) Cr: 2.0 to 15.0% by weight Cr is dissolved in the matrix to enhance the hardenability, and is necessary for improving corrosion resistance and oxidation resistance. If it is less than 15.0% by weight, the effect is small. If it exceeds 15.0% by weight, the seizure resistance is deteriorated and coarse Cr carbides are formed.
% By weight. In particular, 7.5 is required to enhance corrosion resistance.
It is preferable to add at least by weight.

(5) Mo: 2.0 to 15.0% by weight Mo forms a solid solution in a part of the matrix, increases the tempering softening resistance, and combines with C to form an M ₂ C carbide effective for abrasion resistance. I do. If it is less than 2.0% by weight, the effect is small, and 15.0%
If the content exceeds% by weight, M ₂ C carbides are remarkably coarsened. Therefore, the lower and upper limits are set to 2.0% by weight and 15.0% by weight, respectively. (6) V: 2.0 to 15.0% by weight V has the largest tendency to form carbides and forms MC carbides. If less than 2.0% by weight, the amount of MC is small, and sufficient wear resistance cannot be obtained. Also, it is not possible to suppress the coarsening of M ₂ C carbide, and if it exceeds 15.0% by weight, the MC carbide becomes coarse,
The lower limit was set to 2.0% by weight and the upper limit was set to 15.0% by weight because the mechanical properties were reduced. In particular, it is preferable to add 5.0% by weight or more to enhance the effect of MC carbide. (7) W: 10.0% by weight or less W, like Mo, increases the temper softening resistance and forms M ₂ C carbide effective for abrasion resistance.
If the content exceeds 0.0% by weight, M ₂ C carbides become coarse, so the upper limit is set to 10.0% by weight.

(8) Co: 10.0% by weight or less Co mostly forms a solid solution in the matrix to improve the matrix strength,
In particular, the effect is large at high temperatures. If carbides such as MC carbides and M ₂ C carbides are extremely hard and effective for abrasion resistance, the bases of the bases will also wear out in a very short time if the bases do not have the hardness and strength that are effective for wear resistance. Therefore, the strength of the base corresponding to the carbide is required. Co is extremely effective for corrosion resistance. The reason why the upper limit is set to 10.0% by weight is that there is no effect even if it is added beyond that, and that it is expensive. (9) Ni: 0.5 to 10.0% by weight Ni is mostly dissolved in the matrix to improve the strength, hardness, corrosion resistance and quenching property of the matrix. If the amount is less than 10.0% by weight, the amount of retained austenite is increased, and problems such as cracks and rough skin may occur. 0% by weight.

(10) Nb: 0.5 to 5.0% by weight, Ti:
One or more of 0.5 to 5.0% by weight and Zr: 0.5 to 5.0% by weight It is effective to add an appropriate amount of Nb, Ti and Zr to improve the roll performance. Nb, Ti, and Zr are easily bonded to C like V, and by forming MC carbide,
Improves wear resistance. The lower limit at which the effects of Nb, Ti, and Zr are substantially recognized is 0.5% by weight. 5.0
If the content exceeds% by weight, MC carbides are remarkably coarsened. Therefore, the upper limit is set to 5.0% by weight. Also, Nb, Ti, Z
Since both r are expensive, practically, one or more of Nb, Ti, and Zr are selected from the viewpoint of cost.

The feature of this embodiment is that the content of each alloy element is limited, and in the first and third embodiments, −2 ≦ C− (0.06Cr + 0.063Mo +
0.033W + 0.236V + 0.129Nb + 0.2
51Ti + 0.132Zr) ≦ 0,
And in the second embodiment, −2 ≦ C− (0.0
6Cr + 0.063Mo + 0.033W + 0.236
V) ≦ 0. The values in parentheses are the amounts of C (%) that are stoichiometrically balanced as carbides of each alloy element. Cr, Mo, W, V, Nb, Ti and Zr, respectively _{M 23 C 6, M 2 C} , M 2 C, MC,
Since MC, MC, and MC are formed, a carbide coefficient (constant of each alloy element in the above formula) as shown in Table 1 can be obtained depending on the type of these carbides and the atomic weight of each alloy element.

[0020]

[Table 1]

In the first and third embodiments, [C-
(0.06Cr + 0.063Mo + 0.033W + 0.
236V + 0.129Nb + 0.251Ti + 0.13
2Zr)] and [C−
(0.06Cr + 0.063Mo + 0.033W + 0.
When the value of [236V)] is larger than 0, the corrosion resistance is not sufficiently obtained, and the surface roughening resistance is deteriorated. It is not preferable because sufficient reinforcement and abrasion resistance cannot be obtained, and the seizure resistance also deteriorates. Further, conventionally, the roll for the coiler, the mandrel, and the steel sheet conveying roller have been mainly manufactured by the weld overlaying method. However, as in the overlay of the chemical composition of the present embodiment, C, Cr, Mo are used. In the case of alloy materials with high V and V contents, the weldability is poor, and even if careful attention is paid to the preheating temperature, the interlayer temperature, etc. during welding, there is still a risk of cracking, and stable quality is obtained. Was difficult, and the yield and efficiency had to be low.

In a member for hot rolling equipment for steel making using the above-described electromagnetic induction heating method, there is no fear of cracking, so to say, an extremely thick overlay can be obtained in one pass, and high efficiency can be obtained. And a composite material can be obtained at low cost. In addition, since the solidification and cooling are rapidly performed by rapid cooling from the outer surface by the cooling mold and heat removal from the inside by the low-temperature base material, the component composition and the metal composition are extremely uniform, and Cr, Mo, V,
Carbides such as W, Nb, Ti, and Zr are also uniformly and finely distributed, so that a member for hot rolling equipment having sufficient abrasion resistance and corrosion resistance can be obtained.

[0023]

EXAMPLES The abrasion resistance according to the present embodiment is further described below.
An example performed to confirm the operation and effect of a member for a steel rolling hot rolling facility having excellent corrosion resistance will be described together with a comparative example. Table 2 shows the component composition, hardness, and manufacturing method of the outer layer material (facing layer). Comparative materials A, B, C, and D are applied to conventional rolls for coilers and steel sheet transport rollers. It is a typical material. Invention materials E, F, and G are three typical examples of the present embodiment. These comparative materials, and the invention material, after any given quenching, tempering treatment,
Cut out each test piece from the outer layer, which is the layer used,
An abrasion test and a corrosion test were performed to evaluate abrasion resistance and corrosion resistance.

[0024]

[Table 2]

(Results of Wear Test) The wear test was performed at 150 rpm.
With a load of 9 kgf, a 10 mm square test piece is pressed against a 60 mm position from the center of the emery paper, with a load of 9 kgf against a 305 mm diameter emery paper rotating at m.
Abrasion loss was measured after 10 minutes, and a value obtained by dividing the abrasion loss by the area of the test surface was determined to evaluate abrasion resistance. FIG. 2 shows the results of the wear test, and it was found that the material of the present invention has extremely excellent wear resistance as compared with the comparative material. (Results of Corrosion Test) The corrosion test was carried out by placing cooling water for hot rolling equipment in an Erlenmeyer flask having a condenser.
Hold at 0 ° C, length 20mm x width 15mm x thickness 3mm
The surface of the test piece was corroded by immersing the test piece, and after 100 hours, the corrosion products on the surface were removed, and the value obtained by dividing the corrosion loss by the area of the test piece was determined. evaluated. FIG. 3 shows the results of the corrosion test.
It was found that the material of the present invention has extremely excellent corrosion resistance as compared with Comparative material D. From these test results, the material of the present invention has extremely excellent abrasion resistance of twice or more as compared with the conventional roll material, and has a corrosion resistance equivalent to or higher than that of the conventional roll material, and is generally outstanding. It is clear that it has properties. In addition, [C- (0.06Cr +) of invention materials E, F, and G
0.063Mo + 0.033W + 0.236V + 0.1
29Nb + 0.251Ti + 0.132Zr)] are -1.059, -1.054, and -0.907, respectively.
It is.

[0026]

According to the members for hot rolling equipment having excellent wear resistance and corrosion resistance according to the first to third aspects, fine Cr, Mo, V, W, and fine metals are required in the base by a special casting method. The carbides such as Nb, Ti, Zr and the like and the composite carbides of these components are uniformly dispersed in accordance with the above, so that the following effects are obtained. First, the material of the present invention has a hardness of Hs 85 or more and has excellent wear resistance due to the fact that the amount of hard MC carbide is large and that Co and Ni as necessary strengthen the matrix. In addition, since the base is selectively corroded and a form of corrosive wear in which relatively large crystallized carbide is missing is less likely to occur, a high-hardness carbide is stably applied to the surface, and the corrosion resistance is excellent. . As a result, the material of the present invention can significantly improve the life of the roll.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a combination mold according to an embodiment of the present invention, which can be suitably used for manufacturing a member for a steel hot rolling equipment having excellent wear resistance and corrosion resistance.

FIG. 2 is a graph showing a reduction in wear per unit area of a roll using an inventive material and a comparative material.

FIG. 3 is a graph showing a corrosion loss per unit area of a roll using an inventive material and a comparative material.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Combination mold 11 Electromagnetic induction heating coil 12 Fireproof frame 13 Fireproof heating type 14 Cooling type 15 Member for steelmaking hot rolling equipment 16 Elevating device 17 Base material 18 Melting furnace 19 Molten metal 20 Annular gap 21 Overlay layer 22 Borosilicate glass Coating 23 Electromagnetic induction heating coil for preheating 24 Centering device 25 Melting part 26 Melting flux

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B22D 11/00 B22D 11/00 N 19/16 19/16 E C22C 38/38 C22C 38/38

Claims (3)

[Claims] 1. A combination mold in which a cooling mold is integrally disposed below a refractory heating mold provided with an electromagnetic induction heating coil, and a solid or hollow member made of steel is used inside the combination mold. The base material is inserted vertically and concentrically, and a separately prepared molten metal is injected into the annular gap around the base material, the base material is intermittently lowered, and the molten metal is welded to the outer surface of the base material. While being solidified by cooling, a build-up layer is formed on the outer periphery of the base material and subjected to predetermined heat treatment and machining to produce a member for an iron-made hot rolling facility having excellent wear resistance and corrosion resistance. Wherein the components of the molten metal are [C] 0.5 to 2.5% by weight, [S
i] 0.3 to 3.0% by weight, [Mn] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0% by weight, [Mo] 2.
0 to 15.0% by weight, [V] 2.0 to 15.0% by weight,
[W] 10.0% by weight or less, [Co] 10.0% by weight or less, [Nb] 0.5 to 5.0% by weight, [Ti] 0.
One or more selected from the group consisting of 5 to 5.0% by weight, [Zr] 0.5 to 5.0% by weight, and the balance substantially comprises Fe and unavoidable impurity elements; 2 ≦ C
− (0.06Cr + 0.063Mo + 0.033W +
0.236V + 0.129Nb + 0.251Ti + 0.
132Zr) A member for an iron-making hot rolling facility having excellent wear resistance and corrosion resistance, which satisfies the expression of 0. 2. A combination mold in which a cooling mold is integrally disposed below a refractory heating mold provided with an electromagnetic induction heating coil, and a solid or hollow member made of steel is used inside the combination mold. The base material is inserted vertically and concentrically, and a separately prepared molten metal is injected into the annular gap around the base material, the base material is intermittently lowered, and the molten metal is welded to the outer surface of the base material. While being solidified by cooling, a build-up layer is formed on the outer periphery of the base material and subjected to predetermined heat treatment and machining to produce a member for an iron-made hot rolling facility having excellent wear resistance and corrosion resistance. Wherein the components of the molten metal are [C] 0.5 to 2.5% by weight, [S
i] 0.3 to 3.0% by weight, [Mn] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0% by weight, [Mo] 2.
0 to 15.0% by weight, [V] 2.0 to 15.0% by weight,
[W] 10.0% by weight or less, [Co] 10.0% by weight or less, [Ni] 0.5 to 10.0% by weight, and the balance substantially consists of Fe and unavoidable impurity elements. ≤C
− (0.06Cr + 0.063Mo + 0.033W +
0.236V) ≦ A member for hot rolling equipment with excellent wear resistance and corrosion resistance, which satisfies the expression of 0. 3. A combination mold in which a cooling mold is integrally disposed below a refractory heating mold provided with an electromagnetic induction heating coil, and a solid or hollow member made of steel is used inside the combination mold. The base material is inserted vertically and concentrically, and a separately prepared molten metal is injected into the annular gap around the base material, the base material is intermittently lowered, and the molten metal is welded to the outer surface of the base material. While being solidified by cooling, a build-up layer is formed on the outer periphery of the base material and subjected to predetermined heat treatment and machining to produce a member for an iron-made hot rolling facility having excellent wear resistance and corrosion resistance. Wherein the components of the molten metal are [C] 0.5 to 2.5% by weight, [S
i] 0.3 to 3.0% by weight, [Mn] 0.3 to 3.0% by weight, [Cr] 2.0 to 15.0% by weight, [Mo] 2.
0 to 15.0% by weight, [V] 2.0 to 15.0% by weight,
[W] 10.0% by weight or less, [Co] 10.0% by weight or less, [Ni] 0.5 to 10.0% by weight, and [Nb]
One or more selected from the group consisting of 0.5 to 5.0% by weight, [Ti] 0.5 to 5.0% by weight, [Zr] 0.5 to 5.0% by weight, and the balance Consists essentially of Fe and unavoidable impurity elements, and -2 ≦ C- (0.06C
r + 0.063Mo + 0.033W + 0.236V +
0.129Nb + 0.251Ti + 0.132Zr) ≦
A member for hot rolling equipment for steel making, which is excellent in abrasion resistance and corrosion resistance, which satisfies the formula of 0.